Load torque blocking device

ABSTRACT

The invention concerns a load torque lock for automatically locking load-side torques in the case of a decrease or cessation of a drive-side torque having a housing ( 11 ) fixed to a frame, a locking ring ( 17 ) permanently connected to it and a locking body ( 17 ) cooperating with it and revolving on the drive side, whose locking means ( 19, 20 ), on the one hand, clamp on the locking ring ( 17 ) with the occurrence of a load torque by swiveling the locking body ( 17 ) by means of locking elements ( 27, 28 ) of the output shaft ( 15 ) and, on the other hand, release from the locking ring ( 17 ) by swiveling the locking body ( 17 ) back by means of driving elements ( 23, 24 ) of the drive shaft ( 14 ). To avoid undesired friction or defective jamming of the locking means ( 19, 20 ) on the locking ring ( 18 ) by the centrifugal forces of the locking body ( 17 ) it is embodied in such a way that its mass center of gravity (M) lies in the area of the rotational axis of the drive shaft and the output shaft that are aligned with one another.

STATE OF THE ART

[0001] The invention concerns a load torque lock for automaticallylocking load-side torques in accordance with the pre-characterizingclause of Patent claim 1.

[0002] Load torque locks belong to the species of automatically lockinglocks and are used in terms of their functioning with self-switchingfree-wheel mechanisms. They are installed as locking elements in a drivetrain and automatically block the torques initiated by the outputmechanism in one or both directions of rotation when the drivingmechanism is at an standstill, while the torques initiated by the driveside are transmitted in the one or the other direction of rotation. As aresult, torques acting on the load side in a drive train can besupported and locked with the aid of the load torque lock against astationary frame or housing. It forms a safety element, which preventsimpermissible movement of the load side from outside forces or torquesin the case of a decrease or cessation of the driving mechanism. Suchload torque locks are suited especially for use in drive trains withalternating directions of rotation. Using them permits braking systemsor self-locking transmissions that would otherwise be required to bedispensed with.

[0003] Different types of physical effects are already currently beingutilized for load torque locks. Thus, in accordance with DE 30 30 767C2, a coil spring lock is used for manually driven lifting apparatuses,which utilize a frictionally engaged catch band effect. Moreover, theutilization of a frictional clamping effect is known in accordance withG 89 10 857, according to which clamping rollers cooperate with aprofiled output shaft. Further, a load torque lock is described inaccordance with DE-AS 12 49 603, in which a claw coupling is equippedwith double-sided acting clamping bodies.

[0004] These systems are based on frictionally engaged principles ofaction and require a certain pretension of the clamping or lockingelements for continual locking readiness in order to cooperate quicklyand reliably with components fixed to a frame with the occurrence ofload torques. As a result of this pretension of the clamping or lockingelements, which is not completely suspended even in the case of adrive-side drive-through, they remain in continual frictional contactwith the components fixed to a frame. However, this results in highfrictional losses and poor efficiency, which leads to greater warmingwhen high rpms are to be transmitted. The range of application of theload torque locks functioning according to the known frictionallyengaged principles of action is therefore restricted to drivingmechanisms with low rpms.

[0005] Another design of the load torque locks is known from DE 197 53106 C2, which is based on the tilting and swiveling effect. The clampingor locking bodies used there are carried along by rotating the driveshaft with driving elements on an orbit, which has a relatively largeradial distance to the axis of rotation of the load torque lock. Becauseof this off-center arrangement of the clamping or locking bodies,centrifugal forces develop in the case of a drive-side drive-though,which can for their part cause undesired tilting of the clamping orlocking bodies. In fact the patent specification mentions in referenceto FIG. 9 that in order to avoid frictional contact of the clamping orlocking bodies with the clamping or locking ring unit that is fixed to aframe from developing centrifugal forces, these centrifugal forces canbe supported by a certain embodiment via the add-on parts of the outputshaft. However, this is only the case at a certain operating pointdependent upon the driving mechanism's rpms and the torque.

[0006] The attainment at hand attempts to embody a load torque lock insuch a way that an impermissible response of the load torque lock tocentrifugal forces is reliably avoided over the entire rpm range.

ADVANTAGES OF THE INVENTION

[0007] The load torque lock, in accordance with the invention with thefeature given in the characterizing portion of Patent claim 1 has theadvantage that the occurrence of centrifugal forces on the clampingbodies is avoided for the most part by displacing the mass center ofgravity of the clamping bodies to the area of the axis of rotation,which in turn results in reliable avoidance over the entire rpm range ofcentrifugal-force-induced swiveling of the locking bodies and locking ofthe drive load that is thereby triggered. This results in a furtheradvantage that this type of load torque lock can also be used preferablyfor high speed driving mechanisms such as electric motors that driveadjusters or components that move back and forth.

[0008] Advantageous further developments and improvements of thefeatures indicated in Patent claim 1 are yielded from the measureslisted in the sub-claims.

[0009] Thus, the locking body is designed in a simple-to-manufacture andspace-saving manner as a locking disk, which is arranged perpendicularto the axis of rotation in the housing and is preferably embodied to becircular or annular.

[0010] A quick and effective clamping or releasing of the locking diskon the locking ring fixed to the housing is achieved by slightlyswiveling the locking disk so that the locking disk features at leasttwo locking means on different radii and offset from one another aroundan angle in the circumferential direction, of which the one lockingmeans cooperates with the outside of at least one locking ring fixed tothe housing and the other locking means cooperates with its inside.

[0011] In order to counteract any inclination of the locking disk whenthe load torque lock is responding and to avoid an initial axialspringiness of the locking disk, it is proposed that on both front sidesof the locking disk two aligned locking means are each arrangedlaterally reversed, each of which cooperate with one of two lockingrings arranged fixed to the housing on both sides of the locking disk.The locking means in this connection are embodied in a simple andreliable manner as clamping bolts projecting from the front side of thelocking disk on both sides parallel to the axis of rotation.

[0012] In order to achieve a reliable clamping of the clamping bolts onthe locking rings, they are embodied in a structurally rugged andsimple-to-manufacture manner as a locking ring wall projecting from eachfront side of the housing towards the inside until in front of thelocking disk and concentric to the axis of rotation, on whose outsideand inside circumferential surfaces a clamping bolt of the locking diskis each able to engage. Locking means known in the state of the art canalso be used as an alternative to the clamping bolts, whereby then theoutside and inside circumferential surfaces of the locking ring wallmust feature a corresponding locking gear design. Alternatively, in thecase of load torque locks whose possible load torques are relativelysmall, a locking ring wall arranged on both sides of the locking diskcan be dispensed with by arranging it only on the front side of thelocking disk. This allows the axial width of the housing to be reduced.

[0013] For the lowest possible swiveling of the locking disk in order toachieve a quick response and release of the load torque lock, thelocking means are expediently arranged in a radial external area of thelocking disk, whereby the driving elements and the locking elements ofthe drive shaft and the output shaft engage on its radial interior areato swivel the locking disk.

[0014] It is important for the arrangement of the driving and lockingelements that these cooperate as effectively as possible with thelocking disk in order to swivel the locking disk for locking andreleasing the load torque lock when turning the drive shaft or theoutput shaft. For this purpose, a first plane is mentally stretched overthe axis of rotation, which runs through the locking means (clampingbolts) and, related to this first plane, the at least one drivingelement is arranged on the one side and the at least one locking elementis arranged on the other side of this plane, whereby these elementsengage at the locking disk in such a way that they swivel the lockingdisk to release or lock the locking means (clamping bolts) perpendicularto this first plane in the one direction or the other opposingdirection.

[0015] In order to permit a load torque lock to become effective forboth directions of rotation, one driving element and one locking elementare each provided for each direction of rotation, which engage on thelocking disk. Since to lock or release the load torque lock, the lockingdisk may be swiveled independently of the direction of rotation of thedrive shaft and the output shaft only in the one direction or only inthe other opposing direction, the driving and locking elements mustconsequently be arranged for each direction of rotation. For thispurpose, a second plane is stretched over the axis of rotation, whichruns perpendicular to the first plane and, related to the this secondplane, a driving element and a locking element are each arranged toengage on the one side and a driving element and a locking element areeach arranged to engage on the other side of this second plane at thelocking disk.

[0016] In order to guarantee the most defined contact points possiblebetween the driving elements or the locking elements and the lockingdisk, the driving elements are embodied in a simple and rugged manner asdriving bolts projecting from a flange-like end of the drive shaftparallel to the axis of rotation, each of which engages in a largerrecess of the locking disk. In addition, the locking elements areembodied in a corresponding manner as locking bolts projecting from aflange-like end of the output shaft parallel to the axis of rotation,each of which engages preferably together with a spring element in alarger recess of the locking disk.

[0017] It is particularly expedient with respect to the lines ofapplication of the force originating from the driving and lockingelements to swivel the locking disk if, when the locking disk is in aposition of rest, at least one driving element forms a contact pointwith the locking disk on its side facing the first plane and if,moreover, the at least one locking element features a small distance toa contact point with the locking disk on its side facing the firstplane. In this connection, the previously mentioned distance is bridgedin an advantageous manner by the spring element, which is arranged onthe locking bolts serving as the locking element.

[0018] For a compact and rugged embodiment of the load torque lock, itis further proposed that the flange-like ends of the drive shaft and theoutput shaft be positioned on the opposing front sides of the housing.In this connection, the locking disk is arranged in a structurallysimple and safe manner between the spaced-apart, flange-like ends of thedrive shaft and output shaft. Since, due to the position of the contactpoints of the driving and locking elements with the correspondingrecesses of the locking disk, the forces that become effective whenlocking or opening the load torque lock for slight swiveling of thelocking disk run almost perpendicular to the first plane, an opened lockin normal operation simultaneously achieves that no significantfrictional force occurs between the locking ring fixed with the housingand the locking means (clamping bolts) so that it is possible todispense with additional measures for contact free revolution on thelocking ring.

[0019] For the most stable possible positioning of the drive shaft andoutput shaft it is further proposed that the locking disk be providedwith a centric opening, through which a bearing neck of the output shaftprojects, which is accommodated in a bearing inserted in a front-sidebearing bore hole of the drive shaft. Alternatively, this can also takesplace in a reverse manner via a bearing neck of the drive shaftpositioned on the output shaft.

[0020] In order to compensate for any imbalance caused by the lockingmeans of the locking disk, it is expediently proposed to arrange amaterial accumulation on the circumferential area of the locking diskthat is diametrically opposed to the locking means in such a way thatthe mass center of gravity of the locking disk lies as precisely aspossible on the axis of rotation. As an alternative to this materialaccumulation, it is also possible to carry out a material reduction forthe same purpose in the area of the locking means (clamping means),e.g., by bore holes in the locking disk arranged in the circumferentialdirection on both sides next to the locking means (clamping bolts).

[0021] A compact load torque lock can be achieved in an advantageousmanner by the housing being embodied cylindrically inside, whereby aring air gap sufficient for the swivel movement of the locking disk torelease or lock the locking means (clamping bolts) lies between thelocking disk and the inside wall of the housing. In the case of thisembodiment, the locking means of the locking disk engaging on the insidecircumference of the locking ring can also be arranged alternatively onthe outside circumference of the locking disk and engage there byswiveling the locking disk on the inside wall of the housing.

[0022] Instead of driving and locking bolts fastened on the flange-likeends of the drive shaft and output shaft and engaging in the recesses ofthe locking disk, they can be fastened alternatively in an reversemanner also on the locking disk and engage in corresponding recesses ofthe flange-like ends of the drive shaft and the output shaft.

[0023] For a particularly advantageous use of the load torque lock, itis proposed that it be combined with an electric motor into a driveunit, in which the output shaft of the electric motor simultaneouslyforms the drive shaft of the load torque lock. In addition, the loadtorque lock can also be used in a preferred manner in cases where tillnow self-locking transmission with an efficiency of <50% are being used.For this purpose it is proposed that the load torque lock be usedbetween the output shaft of an electric motor and the drive shaft of anon-self-locking transmission unit. Such a system has the advantage thatthe overall degree of efficiency of the system is clearly increasedabove 50% by the use of an easy-running transmission. In addition, thefunctional and/or manufacturing-related swing angle clearances connectedwith a load torque lock are transmitted to the transmission output onlyto a degree that corresponds to the transmission ratio. In addition,rotational movements initiated on the drive side in both directions ofrotation are blocked while maintaining the drive-side possibility ofpower transmission. Due to the improved efficiency of such a system, anelectric motor with a smaller structural shape and the same drive powercan consequently be used with the advantages of cost savings, smallerconstruction space, a lower mass and inertia of masses, better dynamicbehavior, lower consumption of energy and better installationconditions.

DRAWINGS

[0024] Additional details of the invention are explained in more detailin the exemplary embodiment described in the following on the basis ofthe associated drawings. The drawings show:

[0025]FIG. 1 shows a cross-section of a load torque lock in accordancewith the invention according to Line I-I from FIG. 2.

[0026]FIG. 2 shows the same load torque lock in a longitudinal sectionof the housing.

[0027]FIG. 3 shows a schematic block diagram of drive unit made up of anelectric motor and a load torque lock.

[0028]FIG. 4 shows a schematic block diagram of drive system made up ofan electric motor, load torque lock and transmission unit.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0029]FIGS. 1 and 2 show a cross-section or longitudinal section of loadtorque lock 10 in accordance with the invention. It has a stationaryhousing 11 fixed to a frame with an external cylindrically embodiedhousing wall 12 and flange-like front sides 11 a and 11 b, on which adrive shaft 14 with a flange-like end 14 a is pivoted on the one side 11a and an output shaft 15 with a flange-like end 15 a is pivoted on theother side 11 b. The drive shaft and drive shaft 14, 15 lie on a commonaxis of rotation 16. Arranged between their spaced-apart, flange-likeends 14 a, 15 a is a locking body in the form of a locking disk 17 in ahousing 11, which cooperates via locking means with locking rings fixedwith the housing. The locking rings are embodied in the exemplaryembodiment as a locking ring walls 18 projecting from the two frontsides 11 a, 11 b of the housing 11 towards the inside until in front ofthe locking disk 17 and concentric to the axis of rotation 16. Servingas locking elements are two clamping bolts 19 and 20 that are solidlyinserted in the locking disk 17 parallel to the axis of rotation 16,which project from the locking disk 17 laterally reversed on both sides.Thus, on both sides of the locking disk 17, the clamping bolts 19 and 20each form two aligned locking means, which each cooperate with one ofthe locking ring walls 18 fixed to the housing on both sides of thelocking disk 17. The two clamping bolts 19 and 20 are arranged on radiiof varying sizes in the external circumferential area of the lockingdisk 17, whereby the clamping bolt 19 cooperates with the larger radiusto the axis of rotation 16 with the outside 21 and the clamping bolt 20cooperates with the smaller radius to the axis of rotation 16 with theinside 22 of the two locking ring walls 18. In order to be able to clampor release the clamping bolts 19 and 20 to the locking ring walls 18 bya slight swiveling on both sides transverse to the axis of rotation 16,the two clamping bolts 19 and 20 are offset from one another in thecircumferential direction by an angle α, which is approx. 5° in the caseof the example given. The outside and inside 21, 22 of the locking ringwalls 18 thus form working surfaces for the clamping bolts 19 and 20 tofix the locking disk 17.

[0030] While the clamping bolts 19 and 20 are arranged in a radialexternal area of the locking disk 17, driving and locking elements ofthe drive shaft and the output shaft 14, 15 engage in a radial interiorarea to swivel the locking disk 17. In this connection, the drivingelements are formed by driving bolts 23, 24 projecting from theflange-like end 14 a of the drive shaft 14 parallel to the axis ofrotation 16, each of which engages in a larger recess 25, 26 in the formof a bore hole of the locking disk 17. The locking elements in this caseare formed by two locking bolts 27, 28 projecting from the flange-likeend 15 a of the output shaft 15 parallel to the axis of rotation 16,which each engage with a fitted spring element in the form of a ring 29made of elastic material in a larger recess 30, 31 in the form of a borehole of the locking disk 17. By rotating the drive shaft or output shaft14, 15 in the one or the other direction of rotation, the locking disk17 can be swiveled somewhat to one or the other side by a driving bolt23, 24 or locking bolt 27, 28 around a non-fixed, anisotrophic swivelingaxis 32 running between the two clamping bolts 19, 20.

[0031] In the exemplary embodiment according to FIG. 1, the locking diskmust be swiveled somewhat to the right to clamp the clamping bolts 19and 20 on the locking ring walls 18, while it must be swiveled somewhatto the left to release the clamping bolts 19, 20 from the locking ringwalls 18. In order to guarantee that this happens, the driving bolts andlocking bolts 23, 24 and 27, 28 must correspondingly engage on thelocking disk 17. For this purpose, a first plane 33 is stretched overthe axis of rotation 16 running though the clamping bolts 19, 20.Related to this plane 33, the driving bolts 23, 24 of the drive shaft 14are now arranged on the right and the locking bolts 27, 28 of the outputshaft 15 are arranged on the other, left side of this plane 33 engagingat the locking disk 17. In addition, a physical mathematical requirementfor clamping or releasing the locking disk is that to achieve a positionof equilibrium via the so-called tilting, an outside force on the tiltedbody must run through the sectional area of the angle of friction on thecontact locations. The angles of friction running downward and occurringon the contact points between the clamping bolts 19, 20 and the lockingring walls 18 are depicted in FIG. 1. A first angle of friction 34 runsfrom contact point 35 of the upper clamping bolt 19 with the outside ofthe locking ring wall 18 radially inward and a second angle of friction36 runs from the contact point 37 of the inner clamping bolt 20 with theinside 22 of the locking ring wall 18 radially inward. The two angles offriction 34 and 36 are shown opposed and shaded. They form a sectionalarea 38 with crosshatching, through which the aforementioned first plane33 runs. The driving bolts and locking bolts 23, 24 and 27, 28 are nowarranged in such a way in the recesses 25, 26 and 30, 31 of the lockingdisk 17 that, when the locking disk 17 is in a position of rest inaccordance with FIG. 1, the driving bolts 23, 24 of the drive shaft 14each form a contact point 42, 43 with the locking disk 17 on their sidesfacing the first plane 33, on the one hand. On the other hand, thelocking bolts 27, 28 each have a small distance 41 to a contact point39, 40 with the locking disk 17 on their side facing the first plane 33,whereby the elastic ring 29 bridges this distance 41 as a spring elementof the locking bolts 27, 28. Because of this arrangement, the drivingbolts and locking bolts 23, 24 and 27, 28 engage on the locking disk 17in such a way that it can swivel somewhat in the one or the otheropposing direction to release or lock the clamping bolts 19, 18perpendicular to the first plane 33.

[0032] Moreover, the arrangement of the driving bolts and the lockingbolts 23, 24 and 27, 28 shall be selected in such a way that both adrive-through of the drive shaft 14 as well as a triggering of thetorque lock 10 is possible in both directions of rotation by rotatingthe output shaft 15 when there is a lacking driving mechanism. For thispurpose, a driving bolt 23, 24 and a locking bolt 27, 28 for each of thetwo directions of rotation each engage at the locking disk 17. For acorresponding arrangement of the driving bolts and locking bolts, asecond plane 44 is now stretched over the axis of rotation 16perpendicular to the first plane 33. Related to this second plane 14, adriving bolt and a locking bolt 23 and 27 are each arranged on lowerside and a driving bolt and locking bolt 24 and 28 are each arranged onthe upper side of this second plane 44 in order to engage there with thelocking disk 17.

[0033] A feature of the load torque lock 10 that is essential for theinvention is the embodiment of the locking disk 17 in such a way thatits mass center of gravity M lies in the area of the axis of rotation 16of the aligned drive shaft and output shaft 14, 15. Since thearrangement of the clamping bolts 19 and 20 in the outer circumferentialarea of the locking disk 17 would now cause an imbalance, akidney-shaped material accumulation 45 is arranged on thecircumferential area of the locking disk 17 that is diametricallyopposed to the clamping bolts 19, 20 on both sides of the locking disk17 in such a way that the mass center of gravity M of the locking disk17 lies as precisely as possible on the axis of rotation 16. Inaddition, the locking disk 17 is arranged inside the housing 11 in sucha way that a ring air gap 46 sufficient for the swivel movement of thelocking disk 17 to release or lock the clamping bolts 19, 20 liesbetween it and the inside wall 12 a of the outer housing wall 12.Moreover, the locking disk 17 is provided with a centric bore hole 47though which a bearing neck 48 on the flange-like end 15 a of the outputshaft 15 projects. The bearing neck 48 is accommodated in a bearing 49,which is inserted in a front-side bearing bore hole 50 of the driveshaft 14.

[0034] The operation of the load torque lock 10 in accordance with FIGS.1 and 2 is such that, in the position of rest depicted, the locking disk17 is accepted by the driving bolts and locking bolts 23, 24 and 27, 28between the drive shaft and output shaft 14, 15, whereby clamping bolts19, 20 are pressed by the elastic rings 29 of the locking bolts 27, 28with low force against the locking ring walls 18. The load torque lockis therefore pre-tensioned in a defined manner.

[0035] If the shaft 14 is now driven by a driving mechanism (not shown)in the one or the other direction of rotation, then the driving bolts 23and 24 are also consequently rotated to the right or left. In order totransmit this rotation also to the output shaft 15 via the locking disk17, the locking disk 17 must rotate along. This takes place as followswith respect to FIG. 1.

[0036] In the case of a right-hand rotation, a force in the direction ofline of application A occurs at contact point 42 of the driving bolt 23with the locking disk 17. This force runs through the sectional area 38of the two angles of friction 34, 36 originating from the clamping bolts19, 20 with the consequence that, as a result, the locking disk 17swivels around the assumed swiveling axis 32 so far and therebycompresses the elastic ring 29 until this force is absorbed by it atcontact point 39 of the locking disk 17 with the locking bolt 27. As aresult, the contacts of the two clamping bolts 19, 20 at the lockingring walls 18 are practically lifted and the locking ring 17 rotatesfrictionlessly with the drive shaft 15. Since the locking disk 17 alsocarries along the locking bolt 27 via the contact point 39, the outputshaft 15 also rotates along accordingly, whereby, on the one hand, theupper locking bolt 28 with the ring 29 prevents the locking disk 17 fromanother lateral swivel and, on the other hand, a practicallyfrictionless drive-through takes place. Since no centrifugal forcesoccur in the area of the rotational axis 16 even with high rpms on thelocking disk 17 due to its center of gravity M the drive-through is alsokept stable over the entire rpm range.

[0037] On the other hand, in the case of a left-rotating drivingmechanism, a force engages in the contact point 43 of the driving bolt24 with the locking disk 17, which cuts the sectional area 38 of the twoangles of friction 34, 36 in the line of application B starting fromcontact point 43. The consequence of this is that with a left-handrotation, the locking disk 17 swivels from the driving bolt 24 aroundthe swiveling axis 32 so far to the left until this force is absorbed byit at contact point 40 of the locking disk 17 with the locking bolt 28after the compression of the elastic ring 29. In this case as well, thefriction between the clamping bolts 19, 20 and the locking ring walls 18is lifted so that the locking disk 17 can now also rotate along in theother direction of rotation. The rotating locking disk 17 carries alongthe locking bolt 28 in this process so that the output shaft 15 is alsothereby rotated along. Again in this case a transmission of torques thustakes place in drive-through from the drive shaft 14 via the lockingdisk 17 to the output shaft 15, whereby the clamping bolts 19, 20 alsorotate along practically frictionlessly on the locking ring walls 18. Inthis case as well, another lateral swivel of the locking disk 17 isprevented because it is supported on the lower locking bolt 27 at thecontact point 39 with the elastic ring 29.

[0038] In the case of a decrease or cessation of the load-side torque byswitching off or shutting down the driving mechanism (not shown), theload torque lock is supposed to reliably prevent a rotation of the driveshaft by a load coupled. This takes place by swiveling the locking disk17 to the right as follows:

[0039] In the case of the occurrence of a left-rotating (with respect toFIG. 1) load torque on the output shaft 15, when the spring element 29is compressed in the contact point 39 of the lower locking bolt 27 withthe locking disk 17, a force occurs in the line of application C runningthrough this contact point 39, which goes through the sectional area 38of the two angles of friction 34, 36. With this force the locking disk17 is now swiveled somewhat to the right around its swiveling axis 32,whereby the two clamping bolts 19, 20 automatically clamp at theircontact points 35, 37 with the locking ring walls 18 via a so-calledtilting effect. The locking disk 17 is thereby fixed so thattransmission of the torque to the drive shaft 14 cannot occur.

[0040] In the case of a load torque occurring on the output side for arotation of the output shaft 15 to the right, the lock is triggered bythe upper locking bolt 28 and, in this case, with the compression of thespring element 29 in the contact point 40 of the upper locking bolt 28with the locking disk 17, a force occurs in the line of application D,which also cuts the sectional area 38 of the two angles of friction 34,36, and which consequently effects a swiveling of the locking disk 17around the swiveling axis 32 to the right to trigger an automaticclamping of the clamping bolts 19 and 20 on the locking ring walls 18.In the process, the output torque is also absorbed by the locking disk17 and the associated housing 11 locked on the locking ring walls 18 andis not transmitted to the drive shaft 14.

[0041]FIG. 3 shows a schematic representation of the application of aload torque lock 10 in accordance with FIG. 1 and 2 in a drive unit 60in which it is combined with an electric motor 61 of such a type thatthe output shaft 62 of the electric motor 61 simultaneously forms thedrive shaft of the load torque lock 10. Such an application isadvantageous for example in motor vehicles for the driving mechanisms ofwindshield wipers, window lifters, seat adjusters, clutch adjusters andthe like since it permits the possibility of precisely maintaining theachieved intermediate and end positions of the unit, something which isurgently required, e.g., in the case of adjuster driving mechanisms.

[0042]FIG. 4 depicts another application of the load torque lock 10 fromFIGS. 1 and 2 namely a load torque lock in a drive train with atransmission. Since, e.g., in the domain of electrical tools or, e.g.,in the case of cable winches, high-speed electric motorized drivingmechanisms with a self-locking transmission are required, an overallefficiency of clearly under 50% is produced due to the friction lossesof these types of transmissions. According to FIG. 4, it is now plannedthat the load torque lock 10 be used between the output shaft 65 of anelectric motor 66 and a drive shaft 67 of a transmission unit 68 withouta self-locking device, whereby the overall efficiency can be improved toclearly over 50%.

1. Load torque lock (10) for automatically locking load-side torques inthe case of a decrease or cessation of a drive-side torque with themaintenance of the transmission possibility of drive-side torques from adrive shaft (14) to the output shaft (15) of the load torque lock,comprised of a housing (11) fixed to a frame with at least one lockingring (18) permanently connected to it and with at least one locking body(12) cooperating with it and revolving with the drive shaft, whichfeatures locking means (19, 20), which, on the one hand, press againstthe working surfaces of at least one locking ring (18) with theoccurrence of a load-side torque and the cessation of a correspondinglylarge drive-side torque by swiveling at least one locking body in theone rotational direction by means of a locking element (27, 28) of theoutput shaft (15) and which, on the other hand, releases from theworking surfaces of at least one locking ring with the occurrence of adrive-side torque by swiveling at least one locking body in the otherrotational direction by means of a driving element (23, 24) of the driveshaft (14), characterized in that the locking body (17) is embodied insuch a way that its mass center of gravity (M) lies in the area of therotational axis (16) of the drive shaft (14) and the output shaft (15)that are aligned with one another.
 2. Load torque lock according toclaim 1, characterized in that the locking body (17) is designed as alocking disk, which is arranged perpendicular to the axis of rotation(16) in the housing (11) and is preferably embodied to be circular orannular.
 3. Load torque lock according to claim 2, characterized in thatthe locking disk (17) features at least two locking means (19, 20) onradii of varying sizes and offset from one another in thecircumferential direction by an angle (α), of which the one lockingmeans (19) cooperates with the outside (21) of at least one locking ring(18) fixed to the housing and the other locking means (20) cooperateswith its inside (22).
 4. Load torque lock according to claim 3,characterized in that on both front sides of the locking disk (17) twoaligned locking means (19, 20) are each arranged laterally reversed,each of which cooperate with one of two locking rings (18) arrangedfixed to the housing on both sides of the locking disk (17).
 5. Loadtorque lock according to one of claims 2 through 4, characterized inthat the locking means (19, 20) are embodied as clamping boltsprojecting from the front side of the locking disk (17) parallel to theaxis of rotation (16).
 6. Load torque lock according to claim 5,characterized in that the locking rings (18) are embodied as a lockingring wall projecting from each front side (11 a, 11 b) of the housing(11) towards the inside until in front of the locking disk (17) andconcentric to the axis of rotation (16), on whose outside (21) andinside (22) a clamping bolt (19, 20) of the locking disk (17) is eachable to engage.
 7. Load torque lock according to one of claims 3 through6, characterized in that the locking means (19, 20) are arranged in aradial external area of the locking disk (17), whereby the drivingelements (23, 24) and the locking elements (27, 28) of the drive shaft(14) and the output shaft (15) engage on its radial interior area toswivel the locking disk (17).
 8. Load torque lock according to claim 7,characterized in that, related to a first plane (33) stretched over theaxis of rotation (16) and running though the locking means (19, 20), theat least one driving element (23, 24) on the one side of this plane (33)and the at least one locking element (27, 28) on the other side of thisplane (33) engage at the locking disk (17) in such a way that theyswivel the locking disk (17) to release or lock the locking means (19,20) perpendicular to this first plane (33) in the one direction or theother opposing direction.
 9. Load torque lock according to claim 8,characterized in that, in the case of a lock that acts in bothdirections of rotation, one driving element (23, 24) and one lockingelement (27, 28) for each direction of rotation each engage on thelocking disk (17).
 10. Load torque lock according to claim 9,characterized in that, related to a second plane (44) stretched over theaxis of rotation (16) and perpendicular to the first [plane], a drivingelement (23) and locking element (27) each engage on the one side ofthis second plane (44) and a driving element (24) and locking element(28) each engage on the other side of this second plane (44) at thelocking disk (17).
 11. Load torque lock according to one of claims 2through 10, characterized in that the driving elements (23, 24) areembodied as driving bolts projecting from a flange-like end (14 a) ofthe drive shaft (14) parallel to the axis of rotation (16), each ofwhich engages in a larger recess (25, 26) of the locking disk (17). 12.Load torque lock according to one of claims 2 through 11, characterizedin that the locking elements (27, 28) are embodied as locking boltsprojecting from a flange-like end (15 a) of the output shaft (15)parallel to the axis of rotation (16), each of which engages preferablytogether with a spring element (29) in a larger recess (30, 31) of thelocking disk (17).
 13. Load torque lock according to one of claims 8through 12, characterized in that when the locking disk (17) is in aposition of rest, the at least one driving element (23, 24) forms acontact point (42, 43) with the locking disk (17) on its side facing thefirst plane (33).
 14. Load torque lock according to claim 13,characterized in that when the locking disk (17) is in a position ofrest, the at least one locking element (27, 28) features a smalldistance (41) to a contact point (39, 40) with the locking disk (17) onits side facing the first plane (33).
 15. Load torque lock according toclaim 12 and 14, characterized in that the distance (41) is bridged bythe spring element (29) on the locking bolts (27, 28) forming thelocking element.
 16. Load torque lock according to claim 11 and 12,characterized in that the flange-like ends (14 a, 15 a) of the driveshaft (14) and the output shaft (15) are positioned on the opposingfront sides (11 a, 11 b) of the housing (11).
 17. Load torque lockaccording to claim 16, characterized in that the locking disk (17) isarranged between the spaced-apart, flange-like ends (14 a, 15 a) of thedrive shaft (14) and output shaft (15).
 18. Load torque lock accordingto claim 17, characterized in that the locking disk (17) is providedwith a centric opening (47), through which a bearing neck (48) of theoutput shaft (15) projects, which is accommodated in a bearing (49)inserted in a front-side bearing bore hole (50) of the drive shaft (14).19. Load torque lock according to one of claims 2 through 17,characterized in that a material accumulation (45) is arranged on thecircumferential area of the locking disk (17) that is diametricallyopposed to the locking means (19, 20) in such a way that the mass centerof gravity (M) of the locking disk (17) lies as precisely as possible onthe axis of rotation (16).
 20. Load torque lock according to one ofclaims 2 through 19, characterized in that the housing (11) is embodiedcylindrically, whereby a ring air gap (46) sufficient for the swivelmovement of the locking disk (17) to release or lock the locking means(19, 20) lies between the locking disk (17) and the inside wall (12 a)of the outer housing wall (12).
 21. Load torque lock according to one ofthe preceding claims, characterized in that it is combined with anelectric motor (61) into a drive unit (60), in which the output shaft(62) of the electric motor (61) simultaneously forms the drive shaft ofthe load torque lock (10).
 22. Load torque lock according to one of thepreceding claims, characterized in that it is used between the outputshaft (65) of an electric motor (66) and the drive shaft (67) of anon-self-locking transmission unit (68).